Unité INSERM 1093, Université de Bourgogne, Dijon Cedex 21078, France.
Département de neurosciences, Faculté de médecine, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
eNeuro. 2024 Sep 27;11(9). doi: 10.1523/ENEURO.0047-24.2024. Print 2024 Sep.
There is experimental evidence of varying correlation among the elements of the neuromuscular system over the course of the reach-and-grasp task. The aim of this study was to investigate if modifications in correlations and clustering can be detected in the local field potential (LFP) recordings of the motor cortex during the task. To this end, we analyzed the LFP recordings from a previously published study on monkeys that performed a reach-and-grasp task for targets with a vertical or horizontal orientation. LFP signals were recorded from the motor and premotor cortex of macaque monkeys as they performed the task. We found very robust changes in the correlations of the multielectrode LFP recordings that corresponded to task epochs. Mean LFP correlation increased significantly during reach and then decreased during grasp. This pattern was very robust for both left and right arm reaches irrespective of target orientation. A hierarchical cluster analysis also demonstrated similar changes. In focusing on correlations, our study has contributed new insights to the understanding of LFP signals and their relationship to movement. A sliding window computation of the number of clusters was performed to probe the capacities of the LFP clusters for detecting upcoming task events. For a very high percentage of trials (97.89%), there was a downturn in cluster number following the Pellet Drop (GO signal) that reached a minimum preceding the Start of grasp, hence indicating that cluster analyses of LFPs could contribute to signaling an increased probability of the Start of grasp.
在伸手抓握任务过程中，神经肌肉系统的各个元素之间存在着不同程度的相关性的实验证据。本研究的目的是探讨在运动皮层的局部场电位（LFP）记录中，是否可以检测到任务过程中相关性和聚类的变化。为此，我们分析了先前在猴子身上进行的一项关于垂直或水平目标伸手抓握任务的研究中的 LFP 记录。在猴子执行任务时，从他们的运动和运动前皮层记录 LFP 信号。我们发现，多电极 LFP 记录的相关性发生了非常显著的变化，这些变化与任务时期相对应。在伸手过程中，平均 LFP 相关性显著增加，然后在抓握过程中减少。这种模式对于左右手臂的伸手都非常稳健，与目标方向无关。层次聚类分析也证明了类似的变化。通过关注相关性，我们的研究为理解 LFP 信号及其与运动的关系提供了新的见解。通过对窗口计算的聚类数进行计算，以探测 LFP 聚类在检测即将到来的任务事件方面的能力。对于极高比例的试验（97.89%），在 Pellet Drop（GO 信号）之后，聚类数出现下降，在抓握开始前达到最小值，这表明 LFPs 的聚类分析可能有助于发出抓握开始的概率增加的信号。
